Agglomeration is a fundamental process of the chemical industry.
A distinction is made in the art between a mechanical compactation, a thermal agglomeration such as for example sintering, and a chemical aggregation according to the methods described by Browning in Chem. Eng. 71(25), 1987, page 147 or by the document DE-37 16 286 A1.
The aim of these processes is often to obtain granulated particles which can be manipulated more easily than finely dispersed powders. In practice, this may concern fertilizers, which, in granulated form, are easier to distribute on the ground than powders, raw materials for the glass or ceramic manufacture, ashes from combustion or powders and muds collected by an air filter.
A particular application concerns the immobilization of radioactive or toxic and noxious waste in a cement matrix in spherical shape. Thus, these products can be transported pneumatically or wrapped and stored without a risk of proliferation.
The conventional methods for a mechanical compactation have the drawback that there remains always a small quantity of finely dispersed powder. Furthermore, and this applies to all known methods of thermal agglomeration and chemical aggregation, they do not supply particles of a given spherical diameter, but particles of varying shapes and dimensions. Finally, it is desirable to dispose of other methods in order to enlargen the variety of powders which can thus be processed.
The invention thus aims at presenting a process of producing granulated particles, the shape of which is similar to that of a sphere and the dimensions of which are hardly dispersed and can further be influenced by acting on certain parameters of the process. Moreover, the process according to the invention must be able to be utilized with a greater variety of basic powders than the known processes.